Percentage - Tricks for competitive exams

Percentage chapter is one of the most important chapters in the Maths (QA) which gives many questions in every type of competition exams. First of all I want to clear you that this chapter does not contains many formulae. The only way to prepare properly this chapter is to just try to understand the concepts of the questions of this chapter and do the calculation as fast as you can and try to avoid unnecessary calculations.

I have tried to assemble all types of questions which belong to this chapter in this notes. Your suggestions and query questions are admirably invited. Your queries will solved to clear your doubts.

Tricks for Faster calculations:-

Let us first take a natural number 7200 & Follow the following table for calculations:-

100% of 7200 = 1× 7200 = 7200 

75% of 7200 =  3/4 × 7200 = 5400

50% of 7200 =   1/2 × 7200 = 3600

25% of 7200 =  1/4 × 7200 = 1800

12.5% of 7200 =  1/8 × 7200 = 900

10% of 7200 =  1/10 × 7200 = 720

5% of 7200 =  1/20 × 7200 = 360

2.5% of 7200 =  1/40 × 7200 = 180

1% of 7200 =  1/100 × 7200 = 72

0.5% 0f 7200 =  1/200 × 7200 = 36

0.25% of 7200 =  1-400 × 7200 = 18.

Now    32% = [3× 10%] + [2× 1%]

            57.5% = 50% + 10% - 2.5%

                                   The above mentioned table and pattern will help you solve the simplification questions based on percentage with the use of addition & subtraction  and avoiding the traditional time taking multiplication which will save your precious time in examination hall.

 Q.1 solve the following :- 150% of 15 + 75% of 75=?

(a) 75.75        (b) 78.75        (c)135        (d)281.25        (e) None of these

Sol. :- [100% of 15 + 50% of 15] + [75% of 75]      (to be calculated in mind)

       =    [1 × 15 +  1/2 × 15] + [  3/4 × 75]                         (follow & use the table)

       =    [15 + 7.5] + [ 56.25]                                      (to be calculated in mind)

       =    [22.5] + [56.25]                                              (to be calculated in mind)

       =    78.75   (option – b is the answer mark it up)

Q.2 solve the following :-  40% of 240 =?

(a) 60                   (b) 6000                              (c) 960          (d) 600               (e) None of these

Sol. :- [4 × 10%of 240]                                              (to be calculated in mind)

         = [4 × 24]                                                           (to be calculated in mind)

         = 96    (option – e is the answer mark it up)

Try few more Questions yourself and practice more to enhance your skill.

Q1. 37%of 150 - 0.05% of 1000=?

(a) 50         (b) 55                  (c) 55.5               (d) 55.55            (e) None of these

Q2. (43% of 2750) - (38% of 2990) =?

(a) 43.6     (b) 46.3             (c)  44.7            (d)49.3                     (e) None of these

Q3. (9% of 386) x (6.5% of 144) =?

(a) 328.0065       (b) 333.3333          (c) 325.1664        (d) 340.1664    (e)None of these

Q4. 12% of 980 - ? % of 450= 30% of 227      

            

  (a) 14                     (b) 17                              (c) 11           (d) 8                (e) None of these